It's buggy, and it crashes more often than any other app I use. God forbid you try to change the audio device from speakers to headphones in the middle of a call. And then if you try to just call back on your phone, and they want to share their screen, and you go back to your PC and try to join the call from your PC so you can see the screenshare (it's not going to work).
Seriously, with all the money and resources thrown at this company and this app, you'd think it'd be a little more stable, faster, and reliable. I am literally forced to use this app at work...
Or another way to look at it is that the real customers for Teams are IT departments. It makes their lives easier because they don't have to do anything and it meets all the compliance requirements they are supposed to enforce.
Which in turn reflects that the real customers of IT are regulators and auditors. Nobody with decision making power actually cares whether any of the software in use in enterprises works well or not.